Broadwell-E CPU Benchmarks

Broadwell-E has been released a few weeks ago to consumers, and we have had our hands on some samples previous to that. We would like to share some of the relevant specifications of the BW-E family and detail some of the early results we have seen with them.

CPU

i7-6950X

i7-6900K

i7-6850K

i7-6800K

Cores/Threads

10/20

8/16

6/12

6/12

Core Clock

3.00GHz

3.20GHz

3.60GHz

3.4GHz

L3 Cache

25MB

20MB

15MB

15MB

During our testing here at ICC we have seen a 7% Instruction per cycle (IPC) improvement over the HW-E CPUs. Our testing was done utilizing RHEL7 and trivial benchmark tools such as sysbench. The methodology behind the testing was to pit a 5960X @ 4.0GHz vs a 6950X @ 4.0GHz and do several benchmarks that give us different metrics against instruction sets. This means a 4.3GHz 6950X would be nearly equivalent to a 4.6GHz 5960X with the instruction sets that we have put to the test.

The 6950X, along with 2 additional cores, brings 5MB more L3 cache. The total L3 cache for the CPU comes in at 25MB. The increase in L3 is always welcome and will be a great boost in performance in many high-frequency trading (HFT) applications.

With our sample size, the average overclock for the 6950X clocks in between 4GHz – 4.2GHz (update: now to 4.5GHz). These are safe clock speeds that we feel are stable and under control heat-wise. W​e are working around the clock with our vendors to fix issues in the BIOS that are causing testing and production delays for the BW-E platform.

The 6900K 8-core seems to be a bit of a dud at the moment, multiple samples have issues even booting up at 4.5GHz, and nearly impossible to go any higher. Our sample currently (with BIOS issues as well) is hitting 4.4GHz, and having trouble with stability at 4.5GHz.

I would like to stress that these results are with Engineering Samples provided by Intel. This is extremely early in the lifespan of Broadwell-E, but with the results we see in core performance — as we move on through the batches of these CPUs — we will hopefully see better overclocking potential as has been seen in the past generations.